function Layers (type){
    // type tells us what this layer array contains ie highschool, student, zip.
    this.type = type;

    this.student;
    this.school;
    this.zip;

    this.hideAll = function() {
        var layerArray = new Array();
        layerArray.push(this.student);
        layerArray.push(this.school);
        layerArray.push(this.zip);

        while(layerArray.length > 0){
            layer = layerArray.pop();
            if(layer != undefined)
                layer.setMap(null);
            delete layer;
        }

        this.student = undefined;
        this.school = undefined;
        this.zip = undefined;
    }
}
